The invention relates to a cylinder barrel with a surface for receiving a piston, particularly of an internal combustion engine including a surface structure adapted to retain a relatively large oil volume to reduce friction and wear of the surface.
DE 196 29 332 C1 discloses wear resistant cylinder surfaces which assists in reducing the friction of a piston moving in the cylinder. The cylinder surface is hardened by laser treatment whereby, during the hardening procedure, brass particles are deposited on the cylinder surface, which improves oil adherence. The oil retaining capability of the cylinder wall is increased by the brass particles so that the wear of the cylinder surfaces and of the piston is decreased and the life and operational safety of an engine having cylinder surfaces treated in this manner are improved.
In order to reduce oil consumption and also HC emissions, it is however advantageous it the volume of oil retained on the cylinder surfaces is a small as possible. But the oil retaining capability can be reduced only to a certain degree to avoid excessive wear.
DE 35 10 393 C1 discloses a cylinder surface for a piston which includes in the area of the upper dead center position of the piston, an annular zone with a lattice of points having a Ledeburit structure. The zone with the Ledeburit structure points is said to improve the wear and corrosion resistance. Between adjacent Ledeburit structure points, the cylinder surface is radially recessed providing for areas in which additional oil can be retained so as to improve the oil supply to the cylinder surfaces.
It is the object of the present invention to provide a cylinder surface with an optimal lubrication structure providing also for low oil consumption and low HC emissions.